When people come to my office, they are always surprised at how, over the years, they have gained weight. Somehow, without any change in their eating habits, they have put on a few pounds “every year since I had children.”
While there may be many factors contributing to this phenomenon, one important factor is the metabolic effects of losing muscle tissue as you age. On average, adults who do not strength train lose approximately four to six pounds of muscle tissue per decade. Unlike fat, muscle tissue burns calories even when it is resting, and is an important component in your metabolic rate. For most sedentary adults, resting metabolism accounts for about 70 per cent of their daily calorie use.
Consequently, any reduction in muscle mass decreases the amount of calories your body burns every day. Assuming no change in diet, the calories that were previously used to maintain this lost muscle tissue is now stored as fat. Unfortunately, fat does not burn calories; it only stores them. Basically what this means is that if you are not doing activities to maintain your muscle mass as you age, you need to reduce the amount you eat or you will gain weight.
Aside from boosting your metabolism and preventing weight gain, strength training has been shown to provide many other benefits including: improving blood sugar utilization (think: diabetes prevention), reducing resting blood pressure (think: hypertension prevention), improved lipid profile (think: high cholesterol prevention), better vascular condition (think: heart disease prevention), increased gastrointestinal transit speed (think: less constipation), increased bone mineral density (think: osteoporosis prevention), and improved body composition (think: looking hot in your jeans!).
In some studies, strength training was also associated with reduced arthritis pain, fewer falls in the elderly and improvements in depression. Basically, resistance training works to allow you to maintain your independence as long as possible.
Most professional organizations recommend strength training all major muscle groups at least twice a week. This is not enough to make you look like a body builder. Furthermore, if you hate going to the gym, strength training can be done in your house with soup cans and can include daily activities like carrying groceries (or your infant). People starting strength training for the first time may want to consult their doctor and may benefit from seeing a certified professional (such as a physio or trainer) to learn proper technique and appropriate exercises.